1. Field of the Invention
The present invention relates to packaging trays for use in holding food items and, more particularly, relates to a rib reinforced plastic packaging tray, such as used for packaging meat, poultry, fish and other foodstuffs in a supermarket.
2. Discussion of the Prior Art
Plastic packaging trays are widely used in the food processing industry as a convenient and economical way to handle and sell various food items, such as meats, poultry and fish. To keep tray cost to a minimum, it is desirable to decrease wall thickness of the tray as much as possible, but this is limited by the strength which is required of the tray to reliably support and hold a particular item. Heavy items, such as meats, poultry and fish naturally require relatively thick wall structures to ensure they have a sufficient resistance to deflection and bending stresses.
To help reduce wall thickness, while preserving strength, many packaging trays employ strengthening reinforcing ribs at their bottoms and/or sides. However, typical reinforcing ribs have uniform height and width dimensions and extend substantially from tray sidewall to tray sidewall, causing a considerable loss of useable tray volume for packaging food items. Moreover, the ribs do not always provide a sufficient strengthening of the tray, particularly in the larger so-called family pack trays.